Skip to main content
Primary Care Respiratory Journal: Journal of the General Practice Airways Group logoLink to Primary Care Respiratory Journal: Journal of the General Practice Airways Group
. 2011 Aug 2;20(4):421–426. doi: 10.4104/pcrj.2011.00067

Community-acquired pneumonia distinguished from influenza infection based on clinical signs and symptoms during a novel (swine) influenza A/H1N1 pandemic

Masanori Nakanishi 1,*, Yishimasa Yoshida 1, Nobuya Takeda 2, Hirohumi Hirana 2, Takahiro Horita 2, Kazuhiko Shimizu 2, Kazuyuki Hiratani 2, Shigeo Toyoda 2, Takayuki Matsumura 2, Eiji Shinno 2, Akihiro Hutamura 2, Masanari Ota 2, Toshoki Natazuka 2
PMCID: PMC6549881  PMID: 21808939

Abstract

Aims

The numbers of patients with influenza-like illnesses increase during influenza outbreaks. A study was undertaken to distinguish community-acquired pneumonia (CAP) from influenza based on clinical signs and symptoms.

Methods

This retrospective study investigated patients with positive results in the rapid influenza antigen test and those diagnosed with CAP during an influenza A/H1N1 pandemic. Significant factors for predicting risk for CAP within 48 hrs from onset and at diagnosis were selected by multiple regression analysis.

Results

Within 48 hrs of onset and at diagnosis, age, sputum and coarse crackles significantly increased the risk of CAP whereas sick contact, sore throat, and rhinorrhoea significantly decreased the risk of CAP. Duration of illness, sputum, dyspnoea, chest pain, and coarse crackles also significantly increased the risk of CAP at diagnosis.

Conclusions

CAP differed somewhat from influenza even within 48 hrs of onset and the differences became even more evident thereafter.

Keywords: primary care, pulmonary diseases, differential diagnosis, signs, symptoms, community-acquired pneumonia, influenza A/H1N1

Full Text

The Full Text of this article is available as a PDF (305.3 KB).

Footnotes

The authors declare that they have no conflicts of interest in relation to this article.


Articles from Primary Care Respiratory Journal: Journal of the General Practice Airways Group are provided here courtesy of Primary Care Respiratory Society UK/Macmillan Publishers Limited

RESOURCES